1. Field of the Invention
The present invention relates to an electrical connecting apparatus for providing continuity between two devices with a direct coupling type connector, and more particularly, to an electrical connecting apparatus suitable for use between a rotary connector and a steering system of an automobile.
2. Description of the Related Art
A rotary connector is briefly comprised of a pair of housings connected so as to be rotatable relative to each other, and a flexible cable wound in a storage section defined between the housings. Both ends of the flexible cable are electrically led out of each of the housings while being fixed thereto. One of the housings is used as a movable member and the other one is used as a stationary member. When the movable housing is rotated in either clockwise and counterclockwise directions, the flexible cable is wound unwound in the storage section in accordance with the direction of rotation.
The rotary connector thus briefly constructed is incorporated in a steering system of an automobile which is an external device, and used as an electrical connecting means such as an air bag circuit or a horn circuit in such a manner that a movable housing is mounted to a steering wheel which is a rotor member, and a fixed housing is mounted to a combination switch which is a stator member. It is necessary to connect an external connector of the external device, such as an air bag inflator and a horn switch, etc. to the flexible cable of the rotary connector, so the tip of the flexible cable led out of the housing is provided with connector terminals corresponding to the external connector.
Hitherto, as disclosed in U.S. Pat. No. 5,229,544 for example, direct coupling type rotary connectors have been known in which the connector terminals (direct coupler) is fixed to the housing itself, and the external connector of an external device is directly connected to the direct coupler. Since the direct coupler is formed integrally with the housing, such rotary connectors not only provide an easier assembly operation in which the rotary connector is mounted at a predetermined position of the steering system and the direct coupler is simultaneously connected to the external connector, but also simplify the structure and are advantageous in reducing the size thereof, as compared with rotary connectors of the type in which the tip of the flexible cable or a lead wire led out of the housing is provided with a specialized connector.
In the above conventional direct coupling type rotary connectors, the direct coupler is formed integrally with the housing and the direct coupler is connected to the external connector when the rotary connector is mounted at the predetermined position of the steering system. Therefore, unless the direct coupler of the rotary connector and the external connector of the steering system are correctly aligned, it becomes difficult to connect the direct coupler to the external connector. Particularly, when a guide mechanism for guiding the rotary connector to the mounting position of the steering system is adopted for the purpose of improving assembly operability, there arises a problem in that the direct coupler cannot be connected to the external connector when the direct coupler and the external connector are even slightly displaced from each other.
Such a problem also arises in various electrical connecting apparatuses for providing continuity between two devices with a direct coupling type connector.